This invention relates to a cooperative type vehicle collision avoidance system and particularly relates to such systems as can be used upon vehicles for the prevention of collisions.
Several different types of position detecting and control systems for vehicles have been developed for the purpose of preventing one object from striking another. The prior art systems for the most part include devices which are adapted to a vehicle and which continuously transmit and receive radio frequency signals. Each vehicle is also equipped with an antenna unit which receives the transmitted signals from the vehicles within the range of the transmitting vehicle. The received signals are processed and information relating to the position of the transmitting vehicle is determined and is presented to the operator of the receiving vehicle. Examples of this kind of system are disclosed in U.S. Pat. No. 3,235,025 issued to Quinn, U.S. Pat. No. 3,293,600 issued to Gifft, and U.S. Pat. No. 4,030,088 issued to McCullough. Similar systems have also been disclosed for use in aircraft in U.S. Pat. No. 3,345,633 issued to Runge and U.S. Pat. No. 4,298,875 issued to Sullivan.
These systems and other similar prior art collision avoidance systems are limited in their usefulness in an environment where there are several vehicles within the relative proximity of one another. The prior art systems for the most part fail to provide a system which clearly distinguishes the signals transmitted by several vehicles or objects and prevents possible interference of signals received simultaneously by a particular vehicle within the system. The prior art simply does not address the situations wherein a great multitude of vehicles or objects within the same proximity transmit their respective signals in a manner which ensures that the received signals can be attributed to a unique vehicle which is in a dangerous proximity of colliding with another vehicle or object.